简单工厂模式
封装改变,既然要封装改变,自然也就要找到改变的代码,然后把改变的代码用类来封装
csharp
abstract class Operat
{
public double NumberA { get; set; }
public double NumberB { get; set; }
public virtual double GetResult()
{
return 0;
}
}
class Add : Operat
{
public override double GetResult()
{
return NumberA + NumberB;
}
}
class Sub : Operat
{
public override double GetResult()
{
return NumberA - NumberB;
}
}
/// <summary>
/// 工厂类
/// </summary>
class Factory
{
public static Operat GetOperat(string flag)
{
switch (flag)
{
case "1":
return new Add();
case "2":
return new Sub();
default:
return null;
}
}
}